This invention relates to a blow-molded plastic bodies, such as decorative or protective strips, molding, trims, spoilers, bumpers and the like, particularly for use in the automotive industry.
It is known to use blow-molded bodies for the above-outlined purpose. Thus, German Auslegeschrift (application published after examination) No. 2,536,766 discloses a strip-shaped, hollow body which is configured as a closed blow-molded body. Such blow-molded bodies can find a variety of uses as decorative and protective strips.
When used in the automotive industry, however, such blow-molded bodies proved to be disadvantageous in that due to their design as closed blow-molded bodies, their resistance to bending and torsional rigidity was found to be excessive. The rigidity of the bodies may lead to difficulties as early as during their attachment to a base surface by means of mechanical connecting members or by glueing. Due to their significant rigidity and the high resistance to bending coupled therewith, stresses during operation of the automobile reach such a high level that the strips may come loose from the vehicle body after a relatively short period of time or may entirely fall off if mounted by a glue-bond.
German Offenlegungsschrift (application published without examination) No. 3,016,652 discloses a further embodiment of a closed blow-molded body which is provided with bead-like depressions in its surfaces to compensate for differences in heat-caused expansion and contraction. According to this publication, the bead-like depressions also serve to increase the resistance to bending and the energy absorbing effect of the strips. The drawbacks of the prior art are thus not overcome by the structure disclosed in this publication.